The hosts went into half time with a 17-point advantage, thanks to tries from Will Evans and Jordan Olowofela, but the young Blues side battled back to narrow the lead to five points.
Roberts impressed in both attack and defence on his return to Welford Road, and was rewarded for his efforts with a second half score.
Lewis Jones also sniped over from a quick-tap however, a try from former Cardiff Blues back row, Luke Hamilton, proved a decisive blow for the visitors.
Cardiff Blues bring their Anglo-Welsh campaign to a close against London Irish at the Arms Park next Friday before attention turns back to Guinness PRO14 action.
With only a couple of minutes on the clock, an offside in midfield allowed Joe Ford to open the scoring from the boot.
The three-pointer proved to be the only points of the first quarter, as both sides wrestled for dominance in possession and territory.
The best try-scoring opportunity of the opening 20 minutes fell to the visitors, when James Down won a line-out against the head inside the Leicester 22.
Tigers’ defence proved tough to break down, and Steven Shingler tried his luck with a cross-field kick to Rhun Williams, but wing Tom Brady was on hand to gather and call for the mark.
However, Richard Hodges’ side were consistently penalised by referee, Jake Makepeace, and an offside in midfield allowed Ford to find touch on the Cardiff Blues 5m line.
A series of strong drives from the Leicester pack resulted in more penalties against the visitors and a yellow card shown to prop Corey Domachowski.
The home side made the most of the extra man, as Will Evans snuck over from close range for the afternoon’s first try.
Leicester looked to make it a quick fire double as they ventured back into the Cardiff Blues 22.
With only meters between ball and line, they were forced through a number of phases thanks to committed, last ditch defending from the Blues, before lock Down held the ball up from Brady’s attempted touchdown.
However, the pressure continued on the visitors’ defence, eventually creating an overlap on the right for Jordan Olowofela to slide in.
Ford maintained his 100 per cent record from the boot with the conversion, giving his side a 17-point lead heading into the interval.
Both sides struggled to get a foothold in the early stages of the second half, but a strong scrum from the visitors saw Makepeace award a penalty.
Lewis Jones took the quick tap and spread wide through the hands of Steven Shingler, Aled Summerhill and Roberts.
The centre fed Corey Howells on the left, who bumped off his opposite number before the covering defence took down the wing within inches of the line.
However, the attacking pressure continued and the Blues got their first points on the board as numbers on the right hand side allowed Shingler to pop Roberts through for a score on his return to Welford Road.
The momentum was with the visitors, and they returned immediately on the attack inside the Leicester 22. Leicester were penalised on the edge of the 22, allowing Shingler to nudge the ball into the corner.
The initial drive was well defended by the Tigers pack, but Makepeace awarded the Blues a penalty. Jones caught the home defence napping with a quick tap, which saw the number nine sneak over to narrow the gap to five points.
Shingler’s conversion struck the wrong side of the uprights, but Leicester struck back immediately to extend the lead to 12 points. Former Cardiff Blues back row, Luke Hamilton, took advantage of the powering pack to crash over.
The Blues looked to spark an unlikely comeback with 10 minutes remaining, and another quick tap by Jones saw lock Joe Maksymiw shown a yellow card for not retrieving the full 10 meters. However the Blues were unable to break the hosts down and score remained unchanged.